A: Core2Duo, Core i3, i5, i7, and Xeon Intel CPUs with 2 GB of RAM in a Macintosh computer with 2 GB of RAM, and 4 GB for downloading from the Mac App Store (Available in 10.6.6 and later). Unofficially, past upgrades have arbitrarily also required an additional 15% of the hard drive to be free for data.

Q: Are there any pitfalls to watch out for?

A: With all upgrades, backing up your data at least twice has been a given. Hardware can fail independently of downloads and upgrades, though may happen simultaneously. Software may be found to be incompatible that has not been tested with the new upgrade, or combination of other software that might be installed with the upgrade. It is also strongly recommended once your backup is complete, to shut down your computer, remove all but Apple wired keyboard and mouse (notebooks remove all input devices). Then once done, reboot, and go directly to the upgrade distribution system available.

Third party system tools, modification, and "maintenance" applications should be verified as compatible, or removed until known to be compatible. Check with developers how to remove if it is essential to use Lion before those applications become compatible. Most "maintenance" tools that deal with system cache, prebinding, are not really maintenance tools. Ask on forum when are the appropriate times to use them before assuming they should be used for upgrades or otherwise.

Q: How can I get from 10.4 or 10.5 to 10.6.6?

A: Purchase a 10.6 retail installer from an Apple retail or third party reseller. It has a picture of a Snow Leopard on the DVD, and does not say Upgrade, Dropin, or OEM. Install it, and then install the 10.6.6 combo update from: http://support.apple.com/kb/DL1349Q: Is it true that I can only get it from the Mac App Store?

A: Presently this truth is based on current documentation as of the writing of this article. It may change, but we can't speculate as to its change. It has a better chance of changing if users request something different at:

A: A 5 Mbps internet connection can download Lion in 2 hours. A 768Kbps connection can download it in 13 hours. These times do not including installation time, or variabilities in connection speeds from a non-dedicated connection, or background application usage of the internet. Any applications running when the installation process begins might interfere with the installation itself, and they should be quit first. It is unknown at the present time if each individual computer will have to download it separately on the same connected Local Area Network, or if imaging of the downloaded file will be allowed for distribution on certain sized Local Area networks in certain settings (schools, businesses, and homes). This is a question one should post or look for on Apple Support Communities once Lion becomes available through regular channels, to determine if there are any limitations.

Q: When will Lion become available?

A: Sometime in July 2011 according to present forecasts from Apple on their own website.

A: Apple has not said one way or another. If true, it says that developers need to pay close attention to what Apple has said on http://developer.apple.com/ regarding that possibility, and should be updating their software for Universal if not Intel compatibility now. This is another thing which it is highly recommended you discuss with developers you depend on, as well as post on http://www.apple.com/feedback/macosx.html the essential need for Rosetta for your applications in the future. A side effect of this possibility, is that Apple only includes the latest OS, and won't allow earlier Mac OSes on Macs than the Mac's production date. This would mean if not present, newer Macs that Lion's release may also not have Rosetta either. Since at this point it is only speculation, we can't say for certain if it is a concern. However, you should at least give those developers a heads up you are concerned if you need that function. Rosetta allows PowerPC based applications to run on Intel Macs seemlessly, as long as PowerPC drivers and plugins aren't present that would require access to the hardware. The added benefit of Universal compatibility is speed improvements in applications that would run on Intel Macs.

A: Look at Apple menu -> About This Mac -> More Info, and see if you meet the Machine ID and RAM requires under the hardware. 2 GB is required for all These Machine IDs will run Lion:Mac Mini 2,1 and later

MacBook 2,1 and later.

iMac 5,1 and later.

All MacBook Air.

MacBook Pro 2,1 and later

All MacPros.

The Macs with the Machine IDs below will not run Lion (x can be any number):Mac Mini 1,x or PowerMac x,x

PageSender has announced it will. As for Quicken, they are still working hard to get something that will work with Lion, but there are no guarantees. I've heard that Moneydance is a great alternative. Plus pretty much any spreadsheet will do a better job of giving you exactly the numbers you want without guessing what you want. It is a good idea to learn how to use spreadsheets. They are still the original computer killer app and they still work wonders.

As for others, you'll have to search various vendors you depend on to see their announcements. Remember, it isn't released yet. And just because it won't work with Lion does not mean it will stop working on Snow Leopard or earlier. No one is saying you must upgrade your entire computer. You can clone your Mac twice, and partition one for Snow Leopard and the other for Lion until your transition is complete. Remember only upgrade because you have a need. This is really not the place to continue discussion about it, as I'm trying to get this tip published. Please post further questions on the Snow Leopard forum, as long as they don't ask people to violate any non-disclosure agreement, or for pre-release information not released by vendors.

A: Lion's general install that isn't part of the Up To Date program is 4 GB. The Up To Date program has typically been about the same as the full retail but the amount currently is not published. All else being equal, the download time over the internet will take approximately:

A 24 hour day and 15 hours (for a total of a minimum of 39 hours) for 56kbps

Remember the retail 10.6 currently does not include the App Store, and those upgrading from 10.5.8 or earlier will need to both buy the retail 10.6, and download the combo 10.6.6 update, not to mention ensure they have the correct processor and 2 GB of RAM. Finally once it is available, you'll have find out how long approximately it takes to install after the download is complete.

A: Core2Duo, Core i3, i5, i7, and Xeon Intel CPUs with 2 GB of RAM in a Macintosh computer with 2 GB of RAM, and 4 GB for downloading (7 GB after installed) from the Mac App Store (Available in 10.6.6 and later). Unofficially, past upgrades have arbitrarily also required an additional 15% of the hard drive to be free for data.

Q: What applications are compatible with Lion?

A: http://roaringapps.com/apps:table provides a nice third party editable listing for people to include the compatible applications. Many of these compatibility entries came from before Lion's release. Please verify they are correct now that it has been released, and help edit it for more accurate data. Be sure to include any update version of Lion post release that you have found is or is not compatible with it, for the help of others who may be upgrading to Lion the first time.

Q: Are there any pitfalls to watch out for?

A: With all upgrades, backing up your data at least twice has been a given. Hardware can fail independently of downloads and upgrades, though may happen simultaneously. Software may be found to be incompatible that has not been tested with the new upgrade, or combination of other software that might be installed with the upgrade. It is also strongly recommended once your backup is complete, to shut down your computer, remove all but Apple wired keyboard and mouse (notebooks remove all input devices). Then once done, reboot, and go directly to the upgrade distribution system available.

Third party system tools, modification, and "maintenance" applications should be verified as compatible, or removed until known to be compatible. Check with developers how to remove if it is essential to use Lion before those applications become compatible. Most "maintenance" tools that deal with system cache, prebinding, are not really maintenance tools. Ask on forum when are the appropriate times to use them before assuming they should be used for upgrades or otherwise.

Q: How can I get from 10.4 or 10.5 to 10.6.6?

A: Purchase a 10.6 retail installer from an Apple retail or third party reseller. It has a picture of a Snow Leopard on the DVD, and does not say Upgrade, Dropin, or OEM. Install it, and then install the 10.6.6 combo update from: http://support.apple.com/kb/DL1349Q: Is it true that I can only get it from the Mac App Store?

A: Presently this truth is based on current documentation as of the writing of this article. It may change, but we can't speculate as to its change. It has a better chance of changing if users request something different at:

A: First off the 7 GB space limitation on the hard disc after it is installed. Secondly, the size of the download file requires significant time, unless you have a high speed broadband connection. Times expected are below -

A 24 hour day and 15 hours (for a total of a minimum of 39 hours) for 56kbps

Remember the retail 10.6 currently does not include the App Store, and those upgrading from 10.5.8 or earlier will need to both buy the retail 10.6, and download the combo 10.6.6 update, not to mention ensure they have the correct processor and 2 GB of RAM. Finally once it is available, you'll have find out how long approximately it takes to install after the download is complete.

These times do not include installation time, or variabilities in connection speeds from a non-dedicated connection, or background application usage of the internet. Any applications running when the installation process begins might interfere with the installation itself, and they should be quit first. It is unknown at the present time if each individual computer will have to download it separately on the same connected Local Area Network, or if imaging of the downloaded file will be allowed for distribution on certain sized Local Area networks in certain settings (schools, businesses, and homes). This is a question one should post or look for on Apple Support Communities once Lion becomes available through regular channels, to determine if there are any limitations.

Q: When will Lion become available?

A: It became available July 20, 2011.

Q: Which Macs can run Lion?

A: Look at Apple menu -> About This Mac -> More Info, and see if you meet the Machine ID and RAM requires under the hardware. 2 GB is required for all These Machine IDs will run Lion:Mac Mini 2,1 and later

MacBook 2,1 and later.

iMac 5,1 and later.

All MacBook Air.

MacBook Pro 2,1 and later

All MacPros.

The Macs with the Machine IDs below will not run Lion (x can be any number):Mac Mini 1,x or PowerMac x,x

These are some of the most common Questions (Q) and Answers (A) about Lion:

Q: What are the system requirements of the Lion upgrade?

A: Core2Duo, Core i3, i5, i7, and Xeon Intel CPUs with 2 GB of RAM in a Macintosh computer with 2 GB of RAM, and 4 GB (7 GB after installed) for downloading from the Mac App Store (Available in 10.6.6 and later). Unofficially, past upgrades have arbitrarily also required an additional 15% of the hard drive to be free for data.

Q: What applications are compatible with Lion?

A: http://roaringapps.com/apps:table provides a nice third party editable listing for people to include the compatible applications. Many of these compatibility entries came from before Lion's release. Please verify they are correct now that it has been released, and help edit it for more accurate data. Be sure to include any update version of Lion post release that you have found is or is not compatible with it, for the help of others who may be upgrading to Lion the first time. Additionally, as it was released, there is no Rosetta. This means any application that is stated to be PowerPC in the System Profiler, will not work with Lion, and needs a comparable application or upgrade to be compatible. The System Profiler is in Apple menu -> About This Mac -> More Info. Intel and Universal applications are on the whole supported, though may still need some tweaking before every feature is compatible.

Q: Are there any pitfalls to watch out for?

A: With all upgrades, backing up your data at least twice has been a given. Hardware can fail independently of downloads and upgrades, though may happen simultaneously. Software may be found to be incompatible that has not been tested with the new upgrade, or combination of other software that might be installed with the upgrade. It is also strongly recommended once your backup is complete, to shut down your computer, remove all but Apple wired keyboard and mouse (notebooks remove all input devices). Then once done, reboot, and go directly to the upgrade distribution system available. Third party system tools, modification, and "maintenance" applications should be verified as compatible, or removed until known to be compatible. Check with developers how to remove if it is essential to use Lion before those applications become compatible. Most "maintenance" tools that deal with system cache, prebinding, are not really maintenance tools. Ask on forum when are the appropriate times to use them before assuming they should be used for upgrades or otherwise.

Q: How can I get from 10.4 or 10.5 to 10.6.6?

A: Purchase a 10.6 retail installer from an Apple retail or third party reseller. It has a picture of a Snow Leopard on the DVD, and does not say Upgrade, Dropin, or OEM. Install it, and then install the 10.6.6 combo update from:

A: Presently this truth is based on current documentation as of the writing of this article. It may change, but we can't speculate as to its change. It has a better chance of changing if users request something different at:

A: First off the 7 GB space limitation on the hard disc after it is installed. Secondly, the size of the download file requires significant time, unless you have a high speed broadband connection. Times expected are below -

4 GB at:

5Mbps is 2 hours.

at 1 Mbps is 10 hours.

at 384 kbps is 27 hours.

at 56k kbps is 184 hours (nearly 8 days).

If you include the 10.6.6 combo update of 1.06 GB

add 29 minutes for 5 Mbps

145 minutes (2 and 25 minutes) for 1 Mbps

6 and a half hours for 384kbps

A 24 hour day and 15 hours (for a total of a minimum of 39 hours) for 56kbps

Remember the retail 10.6 currently does not include the App Store, and those upgrading from 10.5.8 or earlier will need to both buy the retail 10.6, and download the combo 10.6.6 update, not to mention ensure they have the correct processor and 2 GB of RAM. Finally once it is available, you'll have find out how long approximately it takes to install after the download is complete.

These times do not include installation time, which on a MacBook Pro 3,1 15" installing on a Firewire 800 Newertech Voyager with WD10ACS-322J80 drive, 10.6.7, took 1 hour and a half to complete the installation from double clicking the install command to the registration screen. These times may vary by connection speeds from a non-dedicated connection, or background application usage of the internet. Any applications running when the installation process begins might interfere with the installation itself, and they should be quit first.

The installer just before it starts has in its package contents an InstallESD.dmg file a DVD burnable image to install on additional computers in the home without downloading over again. So if you desire to reinstall without an extra internet download, extract that file, by selecting the installer in the dock, and control-clicking it, and revealing it in the Finder. Next Control-mouse click it, and select show package contents. Inside that folder is a Shared Support folder. That's where you find the DMG.

I am running Leopard 10.5.8 and I bought Lion on a USB for $69. However I am unable to install...I receive an error message that says "You cannot use this version of the application Install Mac OS X Lion with this version of Mac OS X."

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